The present invention relates to an electric power conversion/inversion apparatus, such as, an inverter, etc., and in particular to an electric power conversion/inversion apparatus, being used as a motor driving apparatus for use in an automobile, upon which a high reliability is required.
An inverter according to the conventional art 1, as was shown by a third embodiment in Japanese Patent Laying-Open No. Hei 11-346480 (1999), comprises: two power supply bus bars for inputting DC electric power from a DC power source and a capacitor; a plural number of output bus bars for outputting three-phase AC electric power to a motor; a plural number of semiconductor switching modules, being electrically connected to those power supply bus bars and the output bus bars, for inverting the DC electric power inputted into the three-phase AC electric power, to be outputted; and a heat sink on which are mounted those semiconductor switching modules, the power supply bus bars and the output bus bars.
Explanation will be given on that inverter apparatus according to the conventional art 1, in more details thereof. The plural number of the power supply bus bars comprises a positive (+) power supply bus bar and a negative (xe2x88x92) power supply bus bar. The plural number of the output bus bars is provided in number of three (3), so as to form three-phase thereby. The semiconductor module comprises three (3) parallel circuits, in each of which an IGBT and the reverse-parallel diode are connected, thereby forming each of the arms of a three-phase inverter. One of the phases of the three-phase bridge is formed with two (2) of the arms, and semiconductor modules constructing those two arms are provided on the heat sink through an insulator substrate, a common electrode pattern, and a high temperature soldering, so as to be disposed in parallel at both sides thereof. The output bus bars and the positive (+) power supply bus bar are provided on the heat sink, surrounding the semiconductor switching modules provided in parallel, through a insulator plate with contacting therewith. Furthermore, the negative (xe2x88x92) power supply bus bar is provided on the output bus bars through a insulator plate, with contacting therewith. Also, the negative (xe2x88x92) power supply bus bar is disposed, so as to be located in a middle of the semiconductor switching modules provided in parallel. And, the output bus bars or the power supply bus bars and the semiconductor switching modules are connected therebetween through a wire bonding.
Further, in the inverter apparatus of this conventional art 1, the semiconductor switching modules forming an inverter main circuit and the bus bars are attached on the surface of the heat sink, to be contacted with, while a cooling water path is formed on the reverse surface thereof, to cool it, thereby obtaining small-sizing and a long life-time of the inverter apparatus for an electric car.
Also, the semiconductor apparatus having the semiconductor switching elements therein, according to a conventional art 2, as shown in Japanese Patent Laying-Open No. 2000-49281, comprises: a pair of semiconductor switching elements, each having a positive electrode on one surface thereof while a negative one on the other surface; a circuit board, on which the pair of the semiconductor switching elements are mounted in different directions from each other, having a common land on which the positive electrode of one of the semiconductor switching elements and the negative electrode of the other semiconductor switching element are connected by soldering; and a wiring being positioned above the common land and extending in parallel thereto, on which the negative electrode of the one semiconductor switching elements and the positive electrode of the other semiconductor switching element are connected by soldering.
The semiconductor apparatus according to this conventional art 2 is provided for the purpose of eliminating a wiring of a shape xe2x80x9cLxe2x80x9d therefrom, having a component or portion extending in an orthogonal direction to the substrate, thereby to prevent inductance and/or wiring resistance from being increased due to the same wiring in the orthogonal direction to the substrate, as well as obtaining small-sizing of a package by narrowing the distance between the semiconductor switching elements.
However, with the conventional art 1, the output bus bars and the positive (+) power supply bus bar are provided surrounding the semiconductor switching modules provided in parallel, while the negative (xe2x88x92) power supply bus bar in the middle of the semiconductor switching modules provided in parallel, therefore a plane space of the semiconductor apparatus as a whole comes to be a total of each plane area of the semiconductor switching modules, the output bus bars, and the positive (+) and the negative (xe2x88x92) power supply bus bars, or more. This brings about a problem, in particular in a case where it is applied or used as the electric power inverter for use in an automobile, since the space where it is installed is very restrictive.
Also, according to the conventional art 1, the semiconductor switching modules provided in parallel and the output bus bars which is provided therealong or the power supply bus bars are connected there between by the wire bonding, therefore the wiring as a whole comes to be complex, thereby increasing the circuit inductance and the wiring resistance thereof.
Furthermore, according to the conventional art 1, since heat is radiated from the heat sink on one side of the semiconductor switching modules, the cooling of the semiconductor switching modules as a whole must be done by an amount of heat radiation through the heat sink on that one side thereof, therefore there is a problem that the heat radiation cannot be obtained with certainty. Moreover, since the semiconductor switching modules are provided on the common electrodes only through the soldering, and since, generally the semiconductor switching modules and the electrodes are different greatly in the linear expansion coefficient thereof, there is a problem that the soldering receives a large thermal fatigue from thermal cycles due to the intermittent ON-OFF operation of the semiconductor switching modules.
On a while, according to the conventional art 2, there is no description about the detailed construction for obtaining the small-sizing of the inverter apparatus as a whole, but the semiconductor switching elements and the land or the wiring are contacted only through the soldering, there is also a problem that the soldering receives a large thermal fatigue from thermal cycles due to the intermittent ON-OFF operation of the semiconductor switching elements.
An object, according to the present invention, is to provide an electric power conversion/inversion apparatus, achieving reduction in the circuit inductance and the wiring resistance thereof, while bringing the apparatus to be compact in sized as a whole, thereby obtaining an electric conversion/inversion apparatus having a good installation, as well as a high reliability and an efficiency in the electric power conversion/inversion.
Other object, according to the present invention, is to provide an electric power conversion/inversion apparatus, achieving reduction in the circuit inductance and the wiring resistance thereof, and also mitigating the thermal fatigue against the thermal cycles, while bringing the apparatus to be compact in sizes as a whole, thereby obtaining an electric conversion/inversion apparatus having a good installation, as well as a high reliability and an efficiency in the electric power conversion/inversion.
Further other object, according to the present invention, is to provide an electric power conversion/inversion apparatus, achieving reduction in the circuit inductance and the wiring resistance thereof, and also protecting the electrode surfaces of the semiconductor chips from deterioration due to elapse of time, while thereby obtaining an electric conversion/inversion apparatus having a good installation, as well as a high reliability and an efficiency in the electric power conversion/inversion.
According to the present invention, for accomplishing any one of the above objects, firstly, there is provided an electric power conversion/inversion apparatus, comprising: a plural number of input bus bars for inputting electric power from an outside; a plural number of output bus bars for outputting electric power to the outside; and a plural number of semiconductor chips, being electrically connected to said input bus bars and said output bus bars for converting/inverting the electric power inputted into an output, wherein said plural number of input bus bars include a positive input bus bar and a negative input bus bar, being provided extending in parallel to each other, while said plural number of output bus bars are provided extending in parallel to each other and crossing over said positive and said negative input bus bars in longitudinal directions thereof, said plurality of semiconductor chips are disposed, being put between said positive input bus bar or said negative input bus bar and said plurality of output bus bars at crossing positions thereof, and connected electrically and thermally, to said positive input bus bar in a pole direction consistent therewith while to said negative input bus bar in a pole direction consistent therewith, and further to said common output bus bars in pole directions being different from side by side.
More preferably, in the electric power conversion/inversion apparatus, as defined in the above, said positive input bus bar and said negative input bus bar are elongated in a manner of a straight line and disposed in parallel to each other upon a same plane, while said output bus bars are elongated in a manner of a straight line and disposed in parallel to each other upon a same plane, so that said output bus bars cross over said positive and said negative input bus bars at about right angles, in the longitudinal directions thereof.
Also, more preferably, in the electric power conversion/inversion apparatus, as defined in the above, said positive input bus bar and said negative input bus bar are connected to a positive input terminal and a negative input terminal, being formed in a laminated manner, from a side being same in the longitudinal direction thereof, respectively, while said plural number of output bus bars are connected to output terminals, respectively, from a side being same thereto but different from that of the positive and the negative input terminals, in the longitudinal direction thereof.
Also, more preferably, in the electric power conversion/inversion apparatus, as defined in the above, said semiconductor chips, each one being constructed with a MOSFET having a semiconductor switching element and a diode connected thereto in reverse-parallel direction, are connected between said input bus bars and said output bus bars, while said output bus bars being formed three in number, so that said semiconductor chips form a three-phase bridge, thereby inverting DC electric power inputted into three-phase AC electric power.
Secondly, according to the present invention, for accomplishing any one of the objects mentioned above, there is provided an electric power conversion/inversion apparatus, comprising: a plural number of input bus bars for inputting electric power from an outside; a plural number of output bus bars for outputting electric power to the outside; and a plural number of semiconductor chip carriers, being electrically connected to said input bus bars and said output bus bars for converting/inverting the electric power inputted into an output, wherein said plural number of input bus bars include a positive input bus bar and a negative input bus bar, being provided extending in parallel to each other, while said plural number of output bus bars are provided extending in parallel to each other and crossing over said positive and said negative input bus bars in longitudinal directions thereof, said plurality of semiconductor chip carriers, each having a semiconductor chip including a semiconductor switching element therein and a metal member being electrically and thermally connected to a positive surface and a negative surface on both sides of said semiconductor chip, are disposed, being put between said positive input bus bar or said negative input bus bar and said plurality of output bus bars at crossing positions thereof, and connected electrically and thermally, to said positive input bus bar in a pole direction consistent therewith while to said negative input bus bar in a pole direction consistent therewith, and further to said common output bus bars in pole directions being different from side by side.
More preferably, in the electric power conversion/inversion apparatus, as defined in the above, said metal member is formed of a low thermal expansion metal material having a low linear thermal expansion coefficient being near to that of said semiconductor chip, and is connected to said semiconductor chip through a bonding material.
Also, more preferably, in the electric power conversion/inversion apparatus, as defined in the above, said metal member is formed of a low thermal expansion metal material having a low linear thermal expansion coefficient within a range from 3 to 10.
Also, more preferably, in the electric power conversion/inversion apparatus, as defined in the above, a projection portion and an engagement portion of said semiconductor chip carrier and said input bus bar or said output bus bar are engaged, thereby providing a positioning mechanism for fixing both positions.
Also, more preferably, in the electric power conversion/inversion apparatus, as defined in the above, said metal member has an area being larger than that of a projection area of said semiconductor chip, and a thickness thereof is thin, around from 1 mm to 2 mm in thickness thereof.
Thirdly, according to the present invention, for accomplishing any one of the objects mentioned above, there is provided an electric power conversion/inversion apparatus, comprising: a plural number of input bus bars for inputting electric power from an outside; a plural number of output bus bars for outputting electric power to the outside; a plural number of semiconductor chip carriers, being electrically connected to said input bus bars and said output bus bars for converting/inverting the electric power inputted into an output; and a suppression mechanism for suppressing said input bus bars and said output bus bars onto said semiconductor chip carriers, wherein said plural number of input bus bars include a positive input bus bar and a negative input bus bar, being provided extending in parallel to each other, while said plural number of output bus bars are provided extending in parallel to each other and crossing over said positive and said negative input bus bars in longitudinal directions thereof, said plurality of semiconductor chip carriers, each having a semiconductor chip including a semiconductor switching element therein and a low thermal expansion metal member being electrically and thermally connected to a positive surface and a negative surface on both sides of said semiconductor chip, are disposed, being put between said positive input bus bar or said negative input bus bar and said plurality of output bus bars at crossing positions thereof, and connected electrically and thermally, to said positive input bus bar in a pole direction consistent therewith while to said negative input bus bar in a pole direction consistent therewith, and further to said common output bus bars in pole directions being different from side by side.
More preferably, in the electric power conversion/inversion apparatus, as defined in the above, a ratio between a width and a thickness of said input bus bar is set within a range from 5 to 10.
Fourthly, according to the present invention, for accomplishing any one of the objects mentioned above, there is provided an electric power conversion/inversion apparatus, comprising: a plural number of input bus bars for inputting electric power from an outside; a plural number of output bus bars for outputting electric power to the outside; a plural number of semiconductor chip carriers, being electrically connected to said input bus bars and said output bus bars for converting/inverting the electric power inputted into an output; a case for having said and semiconductor chip carriers built-in; and a cooler for cooling said plural number of input bus bars or said plural number of output bus bars, wherein said plural number of input bus bars and said plural number of output bus bars are provided so that they intersect to each other, said plurality of semiconductor chip carriers, each having a semiconductor chip including a semiconductor switching element therein and a metal member being electrically and thermally connected to a positive and a negative surfaces on both sides of said semiconductor chip, are disposed to be put between said input bus bars and said plurality of output bus bars, at crossing positions thereof, being connected electrically and thermally, to said positive input bus bar in a pole direction consistent therewith while to said negative input bus bar in a pole direction consistent therewith, and further to said common output bus bars in pole directions being different from side by side, said case, being made of plastic as a whole, is molded with said input bus bars or said output bus bars in one body with exposing surfaces thereof on anti-semiconductor side, when being formed from the plastic, and said cooler is disposed on an outside said case, being connected thermally to a surface of the anti-semiconductor side, on which said input bus bars or said output bus bars are exposed, through an electric insulator layer.
More preferably, in the electric power conversion/inversion apparatus, as defined in the above, suppression mechanisms are provided onto said input bus bars or said output bus bars, which are molded with said case in one body, so as to suppress said output bus bars or said input bus bars.